Line a rimmed baking sheet or large plate with parchment paper. Aim for a space that will fit in your freezer.
In a bowl, stir together Greek yogurt, honey (or maple), and vanilla until smooth and evenly sweetened.
Taste and adjust sweetness.
Spread the yogurt onto the lined sheet into an even layer, about 1/4 inch thick. Thinner bark snaps better; thicker takes longer to freeze.
Scatter the berries over the yogurt. If using strawberries, slice them thin so they freeze nicely.
Sprinkle on nuts or seeds and any optional add-ins.
Press gently so toppings stick to the yogurt.
Transfer to the freezer and freeze until solid, about 2–4 hours, depending on thickness and freezer strength.
Once frozen, lift the bark by the parchment and break into pieces. Enjoy right away or store for later.